The invention relates to a Christmas decoration lamp, more particularly relates to a lamp which consists an eared bulblet and a waterproof cap. The conventional Christmas lamp decoration is in series and can be hanged in Christmas trees and later the net-shaped Christmas lamp decoration was developed with ears to hang the wires. The present invention has a bulblet socket with ears and a cap to prevent water from getting in. It mainly comprising a bulblet, a bulblet stand and a bulblet socket. The bulblet is inserted into the bulblet socket, the bulblet is then inserted into the bulblet stand, two filament of the bulblet go through the bulblet socket and expose outside. Two ears are disposed at the circumference of a stopping ring on the bulblet socket, a vertical trough is located on the outer circumference of the ear. Two L-shpaed bars are disposed on the bulblet stand in corresponding to the vertical troughs of the ears. A cap with an opened top has a big and small hollow room for enclosing the bulblet and the bulblet socket. Accordingly, the L-shaped bar of the bulblet stand is inserted into the vertical trough of the ear of the bulblet socket, the big hollow room of the cap encloses the upper of the bulblet stand and the stopping ring of the bulblet socket, while the small hollow room encloses the bulblet, thus can prevent water from getting inside.